If you're not interested in the pump in the seat post then swapping that out for one of the fairly cheap alternatives that appear intermittently on ebay will cut something like 350 grams, that's the biggest bang for buck change at around 20 quid. The bottom bracket might be a little overweight too though the specs have probably varied over the years, you might cut 100g there. . . a change of saddle might cut another 150 grams.
If you don't mind narrow tyres you could go with folding kojaks and lose another 240 grams. . . not cheap though.
The folding pedals probably weigh around 350g a pair and so non folding replacements might shed another 130g.
All in all you might cut 1 kilo at some expense.